Empirically, most low level extortion does seem to be about leaking video. I would see a threat model based on 'criminal wants to extort me for money'. As more reasonable than 'creep wants to look through my computer for creeping'. And it seems like extortion focusses on video, so that is the bigger threat. Even if it is less invasive.

I presume the reason behind this is that video is much more likely to be re-shared. Sending bob a zip of someone's inbox is unlikely to be opened, and even less likely to be shared with strangers. But send bob a video of Alice, and he might open it. Heck, he might not know what the video is until he opens it. So even if he is decent, he might still see it. And if he is less decent and shares it, strangers are much more likely to actually view it.